1. Technical Field
The present invention relates to a method and apparatus for detecting peaks in an optical signal; and more particularly to a method and apparatus for doing the same in an optical channel monitor or other optical device.
2. Description of Related Art
In an optical communication network, information may be communicated from one point to another using a wavelength division multiplexed optical signal, which typically has one or more optical channels respectively centered on one or more optical wavelengths λ1, λ2, λ3, . . . λN. Each optical channel is typically used to carry different information in the optical communication network.
In the optical communication network, an optical channel monitor may be used to sense and/or monitor one or more parameters of the one or more optical channels in the wavelength division multiplexed optical signal. The one or more parameters may include channel presence, channel power, channel signal-to-noise ratio and channel wavelength. The information about the one or more parameters may be used, for example; to assess whether the optical communication network is working properly. For instance, if the power of a channel is too weak, or a channel is not present, or the signal-to-noise ratio of a channel is too low, this is likely to indicate that there is a problem in the optical communication network that must be addressed.
By way of example, U.S. Pat. No. 5,995,255 discloses one such optical channel monitor, entitled “Concatenated Fiber Grating Optical Monitor,” that is a wavelength division multiplexing (WDM) optical monitor based on concatenated fiber gratings and which uses a modulator and detector.